#include <iostream>
#include <cstdio>
#include <string>
using namespace std;

int main()
{
    int up,low;
    string s;
    cin>>s;
    up=low=0;
    for(int i=0;i<s.size();i++)
        (s[i]>='a'&&s[i]<='z')?++low:++up;
    if(up>low)
    {
        for(int i=0;i<s.size();i++)
            cout<<(char)((s[i]>='a'&&s[i]<='z')?s[i]-32:s[i]);
        cout<<endl;
    }
    else
    {
        for(int i=0;i<s.size();i++)
            cout<<(char)((s[i]>='a'&&s[i]<='z')?s[i]:s[i]+32);
        cout<<endl;
    }
    return 0;
}
